The Fiordland Conservation Trust has recently led two translocation projects for the species (tieke).
In last two weeks, 50 were transferred to Five Fingers Peninsula (Tau Moana) in Dusky Sound, from predator-free Chalky Island, joining 138 which were relocated last year.
Another 60 were also transferred to nearby Pigeon Island from Chalky Island.
The project was in conjunction with the Fiordland Lobster company, private donors, local iwi and the Department of Conservation.
Department principal biodiversity ranger Lindsay Wilson said the projects looked to be a 'game-changer'' for the species.
''Given the size of Five Fingers Peninsula, the successful establishment of this population has the potential to significantly improve the tieke's current At Risk classification.''
Fiordland Lobster Company previously funded stoat control on Pigeon Island, which was declared predator free in 2007.
Fiordland Conservation Trust deputy chairman Murray Willans said hopefully the project would result in new tieke populations on both islands.